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Thermodynamics of Cadmium Chloride in t-Butanol - Water Mixtures (w_t-BuOH = 10%, 30%, and 50%) from Electromotive Force Measurements

Renato Tomaš ; Department of Physical Chemistry, Faculty of Chemical Technology, University of Split, Teslina 10, 21000 Split, Croatia
Marija Višić ; Faculty of Natural Sciences and Arts, University of Split, Teslina 12, 21000 Split, Croatia
Ivica Mekjavić ; Department of Physical Chemistry, Faculty of Chemical Technology, University of Split, Teslina 10, 21000 Split, Croatia

Sažetak

The e.m.f. of the cell: Cd(Hg)(l, satd.) | CdCl₂ (m) in a mixture of t-butanol - water | AgCl | Ag with 10, 30 and 50 mass per cent alcohol was measured in the temperature range 293.15-313.15 K at 5 K intervals and in the molality range CdCl₂ 0.002-0.02 mol kg-1. From these values and using literature data for stability constants of the Cd chloride complexes, the values of the standard e.m.f. of the cell E_m°) were obtained at each temperature. These values served to calculate the standard thermodynamic quantities (Δ_rG°, Δ_rH° and Δ_rS°) for the cell reaction, the mean activity coefficients of CdCl₂, and also the standard thermodynamic quantities (Δ_tG°, Δ_tH° and Δ_tS°) for CdCl₂ transfer from water to the investigated mixed solvents.
All of the obtained values were compared with the values for 2-pro-panol - water and acetone - water mixtures; the values for Δ_tH° and Δ_tS° were also compared with those obtained for the transfer of electrolytes KCl, KBr and KI in the t-butanol - water mixtures. The values for enthalpy and entropy of the transfer provided an insight into the structure of the t-butanol - water mixtures.

Ključne riječi

potentiometry; cadmium chloride; t-butanol-water mixtures; thermodynamic quantities; activity coefficients

Hrčak ID:

132061

URI

https://hrcak.srce.hr/132061

Datum izdavanja:

5.6.2000.

Posjeta: 978 *